In recent, the necessity to expand social infrastructures is increasing. Thus, it is necessary to develop downtown areas or populated civilian areas. However, there are frequent occasions where rocks in various forms, etc., are protruded to be obstructive factors of civil works such as construction of roads or tunnels to be established in the areas during the works.
Accordingly, when developing populated civilian areas, precise electronic areas, cultural property areas, and so on, a rock breaking technique is currently and restrictively being used. However, the rock breaking technique has caused productivity reduction, indirect civil complaints, air delay and cost maximization.
Specifically, when a large rock is found out during civil works, a gunpowder blasting method, and a shearing method using a breaker, etc., have been conventionally used to cut the rock. The gunpowder blasting method forms multiple insertion holes on a rock by using a crawler drill or the like, and inserts gunpowder into the insertion holes to blast the gunpowder. In addition, the shearing method using a breaker breaks a rock by continuously hitting part of the rock with a separate breaker.
However, the above-described gunpowder blasting method causes the problem of ground shaking due to explosion and pressure upon the blasting, and when the blasting is conducted in an area surrounded by buildings such as houses, it causes problems resulting in significant damages such as occurrence of cracks in the surrounding buildings.
Further, in case of the shearing method using a breaker, noise and vibration generated when the breaker continuously hits a rock are transferred even to the outside, and thereby, causing serious damages to the peripheries.
Accordingly, in order to solve the problems, there has been developed the technology described in Korean Patent No. 10-0614795. The technology is characterized by including a cooling pipe that is longitudinally inserted into each of a multiple number of holes, which are bored in a rock to contain water, to rapidly freeze peripheral water within the holes, a coolant supplier that injects and supplies a liquid coolant for rapid freezing of the cooling pipe and its peripheral water into the cooling pipe, and a vacuum absorber that absorbs air within the cooling pipe to make the inside of the cooling pipe in the negative pressure state for easy injection of the coolant into the cooling pipe, and collects the vaporized coolant in the cooling pipe, wherein the liquid coolant is injected into the cooling pipe to rapidly freeze the peripheral water of the cooling pipe such that the peripheral rock of the holes is broken by the expansion force generated when the water is cooled and frozen.
With respect to other technical features of the technology, the cooling pipe has a cylindrical structure with its interior space being sealed, wherein in an upper portion of the interior space, there is provided a blocking wall that partitions an upper chamber and a lower chamber, and an injection pipe for injection of a coolant from the outside and an absorption pipe for discharge of interior air and a vaporized coolant penetrate through the top end surface of the cooling pipe to be longitudinally inserted into the upper chamber and the lower chamber, whereby first cooling through the upper chamber and second cooling through the lower chamber can be performed by stages.
Although the technology described in Korean Patent No. 10-0614795 is advantageous in that it can easily break a rock without causing noise and vibration, it is cumbersome since when forming holes in a rock, the holes should have the same size as that of the cooling pipe, and problematic since when the sizes are different, the expansion force is not stably applied to the inner circumference surfaces of the holes formed in the rock.